how the internet works...and why
TRANSCRIPT
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How the Internet works… and why!
Asia Pacific Internet Leadership Program Taipei, TW
26 July 2016
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Internet Fundamentals
• How did we get here?
• Layers and standards
• Internet Addresses– and routing
• Domain Names– and rootservers
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How did we get here…• Initially, research project (’70-’80s)
– Open, cooperative, public domain– “Rough consensus and running code”
• Then, product of liberalisation (’90s)– Also, catalyst for deregulation– Commercial, competitive environment
• Now, public utility and critical infrastructure (since 2000 and beyond)– “Internet governance” is a recent afterthought
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Before the Internet…
… and many more: Novell, Microsoft etc etc etc
ApplicationsApplications
NetworkNetwork
OSOS
HardwareHardware
?
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With the Internet…
Internet Applications
TCP/IPTCP/IP
OSOS
HardwareHardware
… and many more: Novell, Microsoft etc etc etc
☺
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After the Internet…
Internet
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So, why the Internet?• Open
– Free standards and implementations– Low barrier to entry
• Lightweight– “Dumb”: simple and efficient– Intelligence at the edges: in applications and devices
• Global– Uniform, “End-to-End”
• Neutral– By default
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LayersandStandards
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Layers – in the telephone network
Wires
Exchanges
Local Loop
Devices
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Layers in networking – traditional...
Phone/Fax/SMSTV/VOD/conf“The Internet”
Applications
Fixed, Dialup/ISDNMobile/2G
Cable/ADSLInfrastructure
Voic
eVi
deo
Dat
aNetwork
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Layers in the Internet…
13
Voice, email, IMVideo, TV, conf
WWW, +++DNS
Applications
802.11x/WiMaxMobile/4G/LTECable/xDSLxFTTH, ETTH
InfrastructureIn
tern
etNetwork
“Net
wor
k st
ack”
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So, what is a standard?• Standards operate at different levels of the network “stack”
– in fact they define the stack
• A standard (or protocol) is simply an agreement– among members of a community,– on a set of guidelines or rules,– which allow cooperation (interoperability), – sometimes, in a forum such as ISO, ITU, W3C or IETF.
• An open standard is a standard which is– Developed through open and accessible processes – Freely accessible, implementable and usable– Available without barriers such as licenses and fees.– … “ideally”, at least.
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Numbers
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What’s an IP Address?• The fundamental Internet address
– Every device must have a numeric network address– Every address must be unique within the network– Every network must have a range (block) of addresses– IPv4 defined by an Internet standard (RFC 791, 1981)
• A finite “Common Resource”– Address pool is limited (eg 32-bit number = 4 billion addresses)– Managed in the common interest, according to policies
• Please learn to distinguish…– Domain names (rigf.asia) and email addresses ([email protected])– IP addresses (IPv4 vs IPv6)– Intellectual Property!
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IP Addresses in use…
The InternetGlobal Routing Table
4.128/960.100/1660.100.0/20135.22/16…
Global Routing Table
4.128/960.100/1660.100.0/20135.22/16202.12.29.0/24…
Announce202.12.29.0/24
R
202.12.29.0/24
Traffic202.12.29.0/24
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Internet address routing
The Internet
Net
Net
Net
NetNet
NetNet
Net
Net
Net
Net
Global Routing Table4.128/960.100/1660.100.0/20135.22/16…
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Global routing table – IPv4
http://bgp.potaroo.net/as1221/bgp-active.html
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IPv6
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IPv4 vs IPv6• IPv4
– 32-bit* number: 232 = ~4 billion addresses– Example: 202.12.29.142– Existing supply is very nearly exhausted
• IPv6– 128-bit* number: 2128 = 340 billion billion billion billion – Example: FE38:DCE3:124C:C1A2:BA03:6735:EF1C:683D– Existing supply should/must last for many decades
• The transition– Underway since 2000– Much slower than expected– In reality, not needed while IPv4 addresses available
* bit = binary digit
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36 million IPv4 addresses left…
http://www.potaroo.net/tools/ipv4/
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Why IPv6 ?• IPv4 address supply is exhausted
– New networks require addresses– Stop-gap measures are damaging (NAT)
• The Internet is growing fast– Broadband: mobile and wifi– “Internet of Things”
• IPv6 is the only viable option we have now– Much larger address space than IPv4– Enable sustainable growth of the Internet– Support the emergence of new technologies
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Private addresses and NAT
10.0.0.1 ..2 ..3 ..4
The Internet
202.12.29.1 … .2 … .3 … .4
*Network Address Translator – AKA home router, hotspot, etc
NAT*202.12.29.32
ISP202.12.29.0/24
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Private addresses and NAT
Internet
10.0.0.202
202.12.29.32
NAT
?Extn 202
Phone Network
02 6262 9898
PABX
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10.0.0.202
Carrier Grade NAT (CGN)
ISP
CGN
10.255.255.255 10.0.0.1
?
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CGN Challenges
27
1TB per 1K subs per month!
Cable Television Laboratories, Inc. 2012
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It has to be IPv6!
Internet
“Things”
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Good news…
https://www.google.com/intl/en/ipv6/statistics.html
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Good news…
https://stats.labs.apnic.net/ipv6
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Good news…
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Names
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193.0.6.148
196.216.2.12001:42d0::200:2:1
192.149.252.752001:500:4:13::80
2001:13c7:7002:4000::10
202.12.29.211
2001:610:240:22::c100:68b
212.110.167.1572001:41c8:20::19
192.0.32.72620:0:2d0:200::7
People like names…
nixi.inrigf.asia
www.google.com
twitter.com
www.apnic.net
Intgovforum.orgwww.isoc.org
www.icann.org
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Using the DNS
The Internet
www.apnic.net
www.apnic.net?
203.119.102.244
DNS
175.98.98.133 203.119.102.244
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Domain Name System• Converts domain names to IP addresses
– Like a phone book– A “critical infrastructure service” on the Internet– A specialised directory service, essentially
• Highly distributed and reliable– Distributed servers– Distributed administration– Distributed authority (through “delegation”)– Redundancy/secondary services, caching etc– Security deployment via DNSSEC
– Estimate 1T+ queries per day
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DNS hierarchy
whois
www
www www ww
w
.The “root”
net
org
com
asia
in… …TLDs
apnic
iana
….
rigf
nixiSLDs
www.apnic.net.
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DNS authority• Root zone
– Managed by ICANN under USG authority
• TLDs – TLD names are delegated by ICANN– gTLDs to nonprofit and commercial Registry organisations– ccTLDs to authorities specified (mainly) by governments
• SLDs– SLD names are delegated/sold by the TLD registry– Most gTLDs have “open second level”– Most ccTLDs have .com/edu/org/gov/etc or .co/ac/or/go/etc– Some ccTLDs also have open second level e.g. yahoo.jp
• 3rd level– ccTLD: may be subject to registry policy e.g. yahoo.co.jp– Or else may be in the private domain of SLD holds
.
net
apnic
www
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Domain name resolution - detail
.rigf.asianameserver
.asianameserver
Rootnameserver
198.41.0.4
“NS: 128.250.1.21”
“NS: 8.50.200.5”
“A: 132.234.250.31”
“A: 132.234.250.31”
www.rigf.asia?
Localresolverwww.rigf.asia?
210.80.58.34
132.234.250.31
*All IP addresses are fabricated
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What’s in a nameserver?• Authority for a particular zone
– eg “rigf.asia”
• Zonefile records including– A: www = “203.12.45.91” (IPv4 address for this name)– AAAA: www = “2001:FC03::203:EFEF” (IPv6 address)– NS: www = “220.35.35.1” (delegation to another server)
• In real life, much more than this– Caches of recent queries– Secondary (backup) server configurations– Many more record types
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What’s in a root nameserver?• The all-important “root zone file”
• NS (delegation) records for all TLDs– gTLDs such as: .com .org .asia etc– ccTLDs such as: .in .us .cn .ch .tv etc– IDN TLDs: . 网络 (Wǎngluò for net) and . 公司 (Gōngsī for com)
• In fact, there are 13 distinct root operators– Named A, B, C, … L and M– Each can have multiple secondaries– Each can have many “anycast” copies/clones/instances– Now there are many hundreds (500++) of individual root servers
globally
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Root nameservers worldwide
http://root-servers.org
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That’s all folks!
• How did we get here?
• Layers and standards
• Internet Addresses– and routing
• Domain Names– and rootservers